The apparent wind direction will move aft in a gust, putting more pressure on the mainsail's windward side than leeward, making the boat heel excessively... which engages the hull and keel to create the rounding up effect. So.. in gusty conditions you want to use the traveler to change the main's angle of attack to match the change in apparent wind direction without changing the trim of your main.
If the wind speed increase steadily until the boat becomes difficult to steer... you are over powered and you need to reset your trim. The first remedy is to start flattening the sails. Outhaul reduces draft depth, Cunningham moves draft forward, mainsheet imparts twist by easing tension on the leech. Backstay adjustment doesn't do much for the mainsail on a masthead rig such as the C22, but you can use it to help the headsail. (next paragraph). If you don't have a Cunningham you can use the halyard. The vang can help if the boom is past the range of the traveler... which isn't much on the C22. So use the vang to control tension on the leech, the mainsheet to control angle of attack... when the traveler is kaput. Some C22 sailors just vang sheet all the time, btw. Anyway, the goal is to "twist" off the top of the sail to depower it... you'll see it getting flatter as you ease the leech tension.
Your headsail will need some attention also.... to depower the jib, move the jib lead aft.... this will put more tension on the foot, less on the leech, opening the upper part of the sail... "twisting" it off per se. Other things you can do is increase halyard tension to help with draft position...and perhaps using the backstay to put more tension on the forestay to keep it from sagging off.
Or...….... you can just order Don Guillette's Sail Trim guide from this website and pat yourself on the back for making such a wise investment.